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366 have no kindred on the Eastern Continent.

As the philosopher of the nineteenth century claims that "in his hands theory is never divorced from fact," we who are not philosophers complain, as we have the right to do, when they flatly contradict each other and furnish no evidence to fortify their statements. We accept their dicta so long as they agree, but we object to a dictum which contradicts another dictum equally respectable.

May 12, 1877.

To the Editor of the Popular Science Monthly.

In the paper on "Mushrooms," etc., in the last number of your I think Mr. Julius A. Palmer, Jr., uses the name of "Dr. Curtis, of South Carolina," for that of the great mycologist, Dr. Moses A. Curtis, of North Carolina, in connection with letters written to Mr. Sprague on "Mushrooms." Whether that is so or not, I am safe in saying that during our late war Dr. Moses A. Curtis wrote a work on "The Edible Fungi of North Carolina," illustrated with colored drawings by his son (I believe the Rev. Charles Curtis), and this manuscript work is still in existence. It is the result of Dr. Curtis's botanical investigations, as well as of his personal experience, as to which of the mushrooms are fit to eat. Many times, I am told, the good doctor had uncomfortable symptoms after trying a new mushroom, but you may be sure he did not stop until he learned more about it. His researches were begun in the war with a view to furnish such information to his people as would enable them to recognize edible mushrooms, and so supplement the poor diet so universal among even the better classes, but I believe he never cared to publish the work. I deem it but justice to the memory of Dr. Curtis to make this statement.

April 30, 1877.

To the Editor of the Popular Science Monthly.

Will you permit a suggestion as to Mr. Herbert Spencer's descriptive term "negatively quantitative," and his specifications under it? It appears to me to belong to an undesirable class of definitions, because its defining part consists not only in asserting the absence of something, but in so asserting it as to require just as much the assertion of all the other absences that exist. That is to say, Mr. Spencer's definition, and his explanations of it, as cited in the of March, page 611, appear to me to necessarily imply the following preliminary proposition (which I do not think Mr. Spencer meant to imply): "A definition may consist of a statement that a single quality or characteristic is excluded from the thing defined." Now, of course, a definition, to be a good one, must accomplish two things, neither of which the above is: it must specify the qualities which the thing defined does possess; and it must exclude—not some one other, but—all others.

Further: is not the term "negatively quantitative" liable to be misunderstood from ambiguity? It seems to me that it may honestly be taken to mean either of the two following:

1. Being such as to exclude dealing with quantity or quantities.

2. Being such as to include, so far as it does deal with quantities, only what are called "negative quantities."

These are, of course, quite different meanings. It appears to me that Mr. Spencer applied the former, and that Mr. Halsted. in his communication to you, had in his mind the latter. If so, a misunderstanding was pretty likely.

I need not explain the benefit of avoiding the use for one purpose of terms already employed for another. And as I am a sincere admirer of Mr. Spencer, and of his great contributions to the advancement of sound thought, I hope you will not suppose I want to do anything in the way of attacking or fault-finding.F. B. P.

April 8, 1877.

To the Editor of the Popular Science Monthly.

Since the publication, in the May number, of the first part of my article "Gar Pikes, Old and Young," I have had information as to the occurrence of Lepidosteus in Black Lake, near Ogdensburg, New York; in the Patapsco River, Maryland, and in the Edisto, Ashepoo, and Combahee Rivers, South Carolina.

It being commonly supposed that Lapidosteus is rarely found outside of the Great Lakes or the Mississippi River and its tributaries, I shall be much obliged to your readers for any information as to its occurrence elsewhere. Particularly valuable would be facts as to the time and place of spawning; and the eggs or newly-hatched young are greatly desired.